1. Field of the Invention
The present invention relates to a machine translation system for translating a first language into a second language, and more specifically to the system for translating a first language having no morphological distinction between singular form and plural form into a second language having morphological distinctions between the two.
2. Description of the Prior Art
Recently, machine translation systems for automatically translating an input one language sentence into another language sentence by means of a computer have been highlighted. In these machine translation systems, basically an input original sentence is divided into predetermined morphemes (translation units) such as word or phrase by means of morphological analysis grammar (rules for word formation); lexical syntactic information and an appropriate word or phase for translation are determined for each morpheme by retrieving a translation dictionary; the input sentence is syntactically analyzed into an intermediate structure by first-language syntactic analysis grammar to build an intermediate structure; the first-language intermediate structure is transferred into a second-language intermediate structure by structure transfer grammar; and those retrieved translation candidate words are combined by means of second-language syntactic generation grammar in order to generate a second-language sentence.
In these translation processes, where English is translated into German or vice versa, for instance, since these two languages are both formed with singular and plural nouns, features indicative of difference in morpheme between singular and plural nouns of the first language can be applied as they are in determining the singular or plural form of nouns of the second language. However, where Japanese is translated into English, for instance, since the Japanese language has no features indicative of difference in morpheme between the singular and plural nouns, it is necessary to determine whether nouns in the original Japanese sentence should be translated into singular nouns or plural nouns. In addition, where Japanese is translated into German, for instance, since German is formed with various features indicative of difference in adjective, definite article, indefinite article, etc. between singular form and plural form, it is further important to determine whether nouns in the original Japanese sentence are singular or plural.
In other words, in the prior-art translation systems, there exists a problem in that it is impossible to accurately translate a first original language including categories with no difference between singular and plural forms into a second translation language including categories with differences between the two.